If you’d like to contribute, the best approach is to send a well-formed pull request, complete with tests and documentation. Pull requests should be focused: trying to do more than one thing in a single request will make it more difficult to process.
If you have a bug or feature request you can try logging an issue.
There’s no harm in creating an issue and then submitting a pull request to resolve it. This can be a good way to start a conversation and can serve as an anchor point.